Hexahydro-naphthoquinone semicarbazones

ABSTRACT

THE INVENTION IS DIRECTED TO HEXAHYDRO-NAPHTHOQUINONE SEMICABAZONES WHICH ARE PREPARED BY REACTING SUBSTITUTED NAPHTHOQUINONES CYCLIC KETALS WITH THIOSEMICARBAZIDES. THESE PRODUCTS HAVE THERAPEUTIC ACTIVITY AS ANTAGONISTS OF HERPES SIMPLEX VIRUS.

United States Patent Oifice 3,555,044 HEXAHYDRO-NAPHTHOQUINONE SEMICARBAZONES Stephen I. Sallay, Montgomery, Pa., assignor to American Home Products Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Dec. 6, 1967, Ser. No. 688,359 Int. Cl. C07d 15/04 US. Cl. 260340.7 13 Claims ABSTRACT OF THE DISCLOSURE The invention is directed to hexahydro-naphthoquinone semicarbazones which are prepared by reacting substituted naphthoquinones cyclic ketals with thiosemicarbazides. These products have therapeutic activity as antagonists of Herpes simplex virus.

This invention relates to new chemical compounds. More particularly, it relates to novel hexahydro-naphtho quinone semicarbazones. The new hexahydro-naphthoquinone semicarbazones encompassed within the present invention are those defined by the structural formula:

Where R and R when taken separately are the same member selected from the class consisting of lower alkyl having up to about three carbons, and when taken together form a ring and take the form where n is 1 or 2 and R is hydrogen or lower alkyl having up to about three carbons in a straight chain;

R is selected from the class consisting of vinylene (-CH CH-), ethylene (CH -CH and epoxyethylene groups;

R is selected from the class consisting of hydrogen, lower alkyl having up to about three carbons, and adamantyl; and

R is selected from the class consisting of hydrogen, and lower alkyl having up to about three carbons;

Patented Jan. 12, 1971 Typically, the compounds of this invention may be prepared as follows:

- H2N NHCSNH2 l B I A (thiosemicarbazide) l B l A 0 NNH-CSNHz II III ll NNHCSNHOHa The junction of ring A and ring B in the product compounds of this may be either cis or trans. Surprisingly, only the cis compounds show the therapeutic etfects characteristic of the present invention.

The preparation of compound II is described in US. Pat. No. 3,294,817, issued Dec. 27, 1966. The preparation of adamantyl thiosemicarbazide is described in US. patent application, Ser. No. 587,985, filed Oct. 20, 1966, and entitled Antiviral Compounds, now Pat. 3,406,180, granted Oct. 15, 1968. Other starting compounds may be prepared as described in RS. McElhinney, J. Chem. Soc., 9SO955 (1966).

To prepare the hexahydro-naphthoquinone semicarbazones of the invention a cis-hexahydro-naphthoquinone cyclic ketal is dissolved in a lower alkanol, and thiosemicarbazide or a lower alkyl derivative thereof is added. The mixture is heated at a temperature range of about 60 C. to about C., preferably at the reflux temperature, for a period of about thirty minutes to five hours.

When the reaction is complete, the product precipitates and may be recovered by well-known techniques. For instance, the product may be filtered off and refluxed in an alkyl ketone, such as acetone or methylethylketone for 10 to 60 minutes, preferably 15 minutes. Thereafter, the solid product is recovered by filtration. It has been found that the cis-form of the product is relatively insoluble, and care must be taken to recover the pure cisform of the product. Repeated and lengthy refluxing in an alkylketone may be required. During the refluxing, the cis-form of the product dissolves only slightly, about one microgram per cubic centimeter of solvent, but it is believed that during the reflux the crystalline form is changed to a microcrystalline form.

In accord with the present invention, the new and novel hexahydro-naphthoquinone semicarbazones have been found to possess interesting pharmaceutical properties which render them useful as synthetic medicinals. More particularly, the compounds in standard pharmacological 4 n-hexane until crystals start to separate. The filtered crystalline product is twice recrystallized from ethanol. The yield is 3.13 g. of cis-2,3,4a,5,8,8a-hexahydro-1,4- naphthoquinone, cyclic l-(ethylene acetal), 4-(4-methylthiosemicarbazone) having a melting point of 178- tests, have exhibited activity against Herpes Simplex virus 179 C, in mice. Particular members have exhibited additional A nalysis.Calcd. for C H O N S (percent): C, activity. For example, cis-2,3,4a,5,8,8a-hexahydro-1,4- 56.93; H, 7.17; S, 10.83. Found (percent): C, 56.98; H, naphthoquinone, cyclic l-(ethylene acetal), 4-thiosemi- 6.99; S, 10.7. carbazone is also active against Influenza NWS, Vaccinia Following the procedure of Example II and substitut- (IHD) and Varicella viruses. ing each of the starting materials listed below for 4-meth- In order more clearly to disclose the nature of the ylthiosemicarbazide results in the product listed opposite present invention, specific examples of the practice of the it.

Starting Material Product A. 4-propylthiosemicarbazidc Cis-2, 3, 4a, 5, 8, 8ahcxahydro-1,4-naphthoquinonc, cyclic 1- (ethylcnc acetal) 4-propyllthio-semicarbazone. B. 4-(l-adan1antanyl)-3-thioscmicarbazide Cis-2,3, 4a, 5, 8, 8u-hexahydro-1,4-naphthoquinone, cyclic 1,

(ethylene acetal), 4-(1-adamantanyl)-3-thiosemicarba- Z0118.

invention are hereinafter given. It should be understood, EXAMPLES III AND IV h w solely by Way of example a The following procedure is used to determine activity is intended neitherto delineate the scope of the invention against Herpes vinm The hosts may be any Standard nor hmlt tha amblt of the appended clams r perimental animals, such as mice, ferrets and rabbits, and EXAMPLE 1 the like, but mice are the preferred test subjects, and the test procedures described here are in regard to the use of This example illustrates the preparation of cis-2,3,4a,5, m ce as h sts. 8,8a-hexahydro-1,4-naphthoquinone, cyclic 1 (ethylene For Herpes simplex virus mice weighing 10 to 12 grams acetal), 4-thiosemicarbazone. A solution of six grams are us d. Pr f0 1156 all Of the Seed Virus P0015 are (0.028 mole) of cis-2,3,4a,5,8,8a-hexahydro-1,4-naphthotitrated for infectivity, and the challenge dose used is quinone, cyclic l-(ethylene acetal) in 50 ml. ethanol is one which will kill almost all of the non-treated control treated with 2.63 g. of thiosemicarbazide and refluxed for animals (LD 30 minutes. The white crystalline precipitate is filtered off Herpes simplex is inoculated intra-peritoneally. The and refluxed in 200 ml. of methylethylketone for 15 soluble compounds to be tested are dissolved in an isominutes. The hot suspension is filtered and 4.76 g. of tonic solution while the insoluble compounds to be tested cis-2,3,4a,5,8,8a-hexahydro-1,4'naphthoquinone, cyclic 1- are ground, then suspended in 0.5 percent carboxymethyl- (ethylene acetal), 4-thiosemicarbazone is obtained. The cellulose (CMC) or the like. product has a melting point of 190191 C. The test compounds are then administered at various Based on the formula C H N O S, it is calculated that 40 dose levels depending upon the activity of the compound, the elemental analysis for the product would be 55.50 each dose level being orally administered to each of a percent carbon, 6.81 percent hydrogen, and 14.94 percent group of ten mice. Two groups of ten mice each are not nitrogen. The product is analysed and the elemental contreated with the test compound and are used as controls. tent is found to be 55.23 percent carbon, 6.58 percent Treatment is delayed until after infection, and the best hydrogen, and 15.11 percent nitrogen. The foregoing may dosage schedule used is determined for each compound. be expressed: The observation period for mice infected with Herpes sim- Analysis.Calcd. for C H N O S (percent): C, plex virus is 14 days. 55.50; H, 6.81; N, 14.94. Found (percent): C, 55.23; The parameters used for evaluating the effectiveness of H, 6.58; N, 15 .11. the test compounds are percentage of survivors, geometric Following the procedure of Example I, substituting mean survival time, and the Rank T test. When there are each of the starting materials listed below for cis-2,3,4a, 5,8,8a-hexahydro-1,4-naphthoquinone, cyclic l-(ethylene acetal) results in the product listed opposite it.

survivors among the control animals, :1 Rank T test is employed. The test compares the pattern of deaths among the treated animals with the pattern of deaths among the Starting Material Product;

A. Cis6,7-epoxy-2,3,4a,5,8,8a-hexahydro-l,4-

naphthoquinone, cyelie l-(ethylcne acetal).

B. (Dis-2,3,4a,5,8,8a-hexahydro-l,4-naphthoquinonc-5-propyl, cyclic l-(ethylene acetal).

C. (Dis-2,3,4a,5.8,8a-hcxahydro-1,4-naphthoquinonc cyclic-l-(-1-propyl-1,3 propancdiyl) acctnl.

. Cis-2,3,4a,5,8,8a'hexahydro-l,4-naphthoquinone, cyclic l-trimethylcnc acctal.

. Cis-2,3,4a,5,8,8a-hexahydro-1,4-naphthoquinone, cyelie1-(l-mcthylethylcnc)acctal.

. (Dis-23,43,5,8,8a-hcxahydrop-mothyl-l,4

naphthoqninonc, cyclic l-(cthylene acetal).

. Cis-2,3,4a,5,8,8a-licxahydro1,4-naphthoquinonc-dipropyl acct/a1.

. Cis-2,3,4a,5,8,8a-hcxahydro-l,4-naphthoquinone-dimethyl-acctal.

Cis-6,7-epoxy-2,3,4a,5,8,8a'hexahydro-1,4-naphthoquinone,

cyclic l-(ethylenc acetal) 4thiosemicarbazone.

Cis-2.3,4a,5,8,8a-hexahydro'1,4-naphthoquinonc-S-propyl,

cyclic l-(ethylenc acetal), 4thiosemicarbazonc.

Cis-2,3,4a,5,8,8a hexahydro-1,4-naphthoquinone cyclic-l- (-l-propyl-1,3 propancdiyl) acetal, t-thioscmicarbazonc.

Cis2,3,4a,5,8,8a-hcxahydro-1,4-naphtlioquinone, cyclic 1- trimethylcne acetal, 4'tliiosemicarbazone.

C1s-2,3,4a,5,8,8a-hcxahydlo-l,4-naphth0quin0n0, cyclic-1- (Lmethylcthylcnc)acetal, 4-thioscmicarbazone.

Cis-2,3,4a,5,8,8a-hexahydro-5-methyl-1,4-naphthoquinone, cyclic l-(ethylene acetal), 4-thiosemicarbazone.

C1s-2,3,4a,5,8,8a-hexahydro-1 ,4-naphthoquinonc-dipropylacctal, 4-thiosen1icarbazonc.

Cis-2,3,4a,5,8,8a-hcxahydro-1,4-naphthoquinone-dimcthylacetal, 4-thioscmiearbazone.

EXAMPLE II This example illustrates the preparation of cis-2,3,4a, 5,8,8a-hexahydro-1,4-naphthoquinone, cyclic l-(ethylene acetal), 4-(4-methylthiosemicarbazone). Following the procedure of Example I, 6.0 g. of cis-2,3,4a,5,8,8a-hexahydro-1,4-naphthoquinone, cyclic-l-(ethylene acetal) are refluxed with 3.03 g. of 4-methylthiosemicarbazidc for 15-60 minutes. The hot reaction mixture is treated with by the test compounds is shown in Table I. The results of increased by small increments until the optimum effect the challenge are shown in Table 11. under the circumstances is reached. It will generally be TABLE I.CHALLENGE WITH THE COMPOUNDS OF THIS INVENTION Post-infection treatment, mierogram g) per mouse Number Example Compound V rus 1 hr. 717% hrs. 44 hrs. 70 hrs. 95 hrs. Total, ug of hosts III:

""""""" Cis-2, 3, 4a, 5, 8, 8a-hexahydro-1, 4- 100 100 100 50 50 400 10 naphthoquinonacyclic l-(ethylene Herpes Simplex...{ 8 g g 8 8 3 acetal) i-thlOSQmlCfilbflZOllG. 0 0 0 0 0 0 10 2hrs. 23 hrs. 48 hrs. 72 hrs. 97 hrs.

Cis-2, a 4 a, 5. e, 8a-hexahlydioglgfi-l 1 g nap oqumone,eyc1c e yone acetal) 4-methylthiosemicar- Herpes slmplex g 8 g 8 8 g bazone. 0 0 0 0 0 TABLE II.RESULTS 0F CHALLENGE OF TABLE I Deaths on day Survivors Example 6 7 8 9 10 11 12 13 Number Significance Rank 'I 2 3 0 0 0 0 0 4 P 0.05 Not applicable. 3 0 1 1 0 0 0 5 P 0.05 Do. 3 4 1 1 1 0 0 None Contro1 Control. 4 2 2 0 0 0 0 1--..do Do.

0 4 1 l 1 0 0 2 Not significantun P 0.05. 3 1 2 0 o 0 1 3 d 1 0.05. 0 4 1 0 1 0 0 6 2 0 0 0 0 o 6 1 2 0 0 1 o The absence of a dose response relationship is a charfound that when the composition is administered orally, acteristic of certain anti-viral agents. Any response at larger quantities of the active agent will be required to any dosage is a positive indication of anti-viral activity produce the same effect as a smaller quantity given parenof the compound utilized. The reason for the absence of terally. In general, the compounds of this invention are a dose response is uncertain. Without wishing to be bound most desirably administered at a concentration level that by a theory of operation it is believed that the response will generally afford effective results without causing any may be due either to the fact that a minimum dose trigharmful or deleterious side effects. gers an unknown host response mechanism or that only The terms and expressions which have been employed a minute amount of the test compound goes into soluare used as terms of description and not of limitation, tion regardless of the amount of insoluble compound in 40 and there is no intention in the use of such terms and exthe dose. pressions of excluding any equivalents of the features It has been found that the physical form of the test shown and described or portions thereof, but it is recogcompound is important. Best results are obtained by minized that various modifications are possible within the cronization. That is, by grinding the test compound to a scope of the invention claimed. maximum particle size of less than five microns 5,u). What 18 clalmcd 1S! As shown in Table II, an effective dose range against 1- A compound havlng the structural formula: Herpes simplex virus has been found to be 0.5 micro- RIQ 2 gram to 4 milligrams in mice weighing 10 to 12 grams. I

When the compounds of this invention are employed as described above, they may be administered alone or I in combination with pharmaceutically acceptable car- R3 I rlers, the proportion of WhlCh is determined by the solu- 0 i H bility and chemical nature of the compound, chosen route NNHCSNHR;

of administration and standard pharmaceutical practice. For example, they may be administered orally in the form where R and R when taken separately are the same of tablets or capsules containing such excipients as starch, member selected from the class consisting of lower alkyl milk, sugar, certain types of clay and so forth. They may having up to three carbons, and when taken together are be administered sublingually in the form of troches or [(CH )nHC-R where n is 1 or 2, and R is lozenges in which the active ingredient is mixed with suhydrogen or lower alkyl having up to three carbons in a gar and corn syrups, flavoring agents and dyes; and then straight chain;

dehydrated sufficiently to make it suitable for pressing R is selected from the class consisting of vinylene, into a solid form. They may be administered orally in ethylene and epoxyethylene groups;

the form of suspensions or solutions which may contain R is selected from the class consisting of hydrogen, coloring and flavoring agents. The solutions may be inlower alkyl having up to three carbons, and adamantyl; jected parenterally, intramuscularly, intravenously, or R is selected from the class consisting of hydrogen subcutaneously. For parenteral administration they may and lower alkyl having up to three carbons.

be used in the form of sterile solutions containing other 2. A compound as described in claim 1 which is: cissolutes, for example, enough saline or glucose to make 2, ,4, a-hexahydro 1,4 naphthoquinone, cyclic lthe solution isotonic. (ethylene acetal), 4-thiosemicarbazone.

The dosage of the present therapeutic agents will vary 3. A compound as described in claim 1 which is: cis- With the form of administration and the particular com- 2,3,4a,5,8,8a-hexahydro 1,4 naphthoquinone, cyclic 1- pound chosen. Furthermore it will vary with the partichylene acetal), 4-(4-methylthiosemicarbazone). ular subject under treatment. Generally, treatment is ini- 4. A compound as described in claim 1 which is: cistiated with small dosages substantially less than the opti- P Y- Xahydro 1,4 naphthoquin mum dose of the compound. Thereafter, the dosage is cyclic l-(ethylene acetal) 4-thiosemicarbazone.

5. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a-hexahydro-l,4-naphthoquinone 5 propyl, cyclic l-(ethylene acetal), 4-thiosemicarbazone.

6. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a-hexahydro 1,4 naphthoquinone, cyclic l- (-1-propyl-1,3 propanediyl) acetal, 4-thiosemicarbazone.

7. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a-hexahydro-1,4-naphthoquin0ne, cyclic l-trimethylene acetal, 4-thiosemicarbazone.

8. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a-hexahydro-1,4-naphthoquinone, cyclic-l-(lmethylethylene)acetal, 4-thiosemicarbazone.

9. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a hexahydro S-methyl-1,4-naphthoquinone, cyclic l-(ethylene acetal), 4-thiosemicarbazone.

10. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a hexahydro 1,4 naphthoquinone-dipropyl acetal, 4-thiosemicarbazone.

11. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a hexahydro 1,4-naphthoquinone-dimethylacetal, 4-thiosemicarbazone.

12. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a hexahydro 1,4 naphthoquinone, cyclic 1- (ethylene acetal), 4-propylthiosemicarbazone.

13. A compound as described in claim 1 which is: cis- 2,3,4a,5,8,8a hexahydro 1,4 naphthoquinone, cyclic 1- (ethylene acetal), 4 (1 adamantanyl)-3-thi0semicarbazone.

References Cited Palande, et al., Chemical Abstracts, vol. 63 (1965), cols. 4216g-4218a (Abstract of article taken from Indian J. Chem. v01. 3 (3), 1965, pp. 117-20).

ALEX MAZEL, Primary Examiner J. H. TURNIPSEED, Assistant Examiner US. Cl. X.R. 

